Two-dimensional(2D) periodical Au and indium tin oxide(ITO) nanocomposite arrays have been fabricated based on a self-assembled nanosphere lithography technique. A button-shaped Au nanoparticle was formed on each holl...Two-dimensional(2D) periodical Au and indium tin oxide(ITO) nanocomposite arrays have been fabricated based on a self-assembled nanosphere lithography technique. A button-shaped Au nanoparticle was formed on each hollow hemisphere-shaped ITO shell. Importantly, the underlying formation mechanism during the thermal treatment has been thoroughly explored by comparing structures resulting from different deposition conditions in detail. Compared to the Au nanoparticle arrays without ITO shells, the Au/ITO nanocomposite arrays showed a stronger localized surface plasmon resonance effect and higher absorption in the near-infrared(NIR) region, benefiting from the free-electron interaction enhancement between Au and ITO. The nonlinear optical properties were investigated using a modified femtosecond intensity-scan system, and the results demonstrated Au/ITO nanocomposite arrays with a remarkable two-photon absorption saturation effect for femtosecond pulses at 1030 nm. The versatile NIR optical responses indicate the great potential of the elaborately prepared 2D periodical Au/ITO nanocomposite arrays in many applications such as solar cells, photocatalysis,and novel nano optoelectronic devices.展开更多
Currently,the fundamental judgment that China remains in an important period of strategic opportunities for its development has not changed,however new changes have taken place in the nature and the conditions of this...Currently,the fundamental judgment that China remains in an important period of strategic opportunities for its development has not changed,however new changes have taken place in the nature and the conditions of this period.On a higher starting point of development,China is faced with unprecedented opportunities for development as well as challenges unknown before.展开更多
This paper constructs a fixed effect model to study the impact of turnover of local government officials on local air quality,and the mechanism through which this effect takes place,using data from 282 prefecture-leve...This paper constructs a fixed effect model to study the impact of turnover of local government officials on local air quality,and the mechanism through which this effect takes place,using data from 282 prefecture-level cities in China from 2015 to 2019.This research shows that turnover of local government officials led to a decline in local air quality,mainly due to a“responsibility gap period.”It also found that the heterogeneity of officials and the difference in the implementation of political initiatives by cities affected the length of the“responsibility gap period”-the shorter it was,the lower the air pollution was during official turnover.Air pollution in China is still severe and the Chinese central government should therefore further reform the turnover system to improve local air quality during the turnover of key local officials by shortening the“responsibility gap period.”展开更多
基金Funding.National Natural Science Foundation of China(NSFC)(61308087,61405224,61522510,61675217)Natural Science Foundation of Shanghai(16ZR1440300)+4 种基金China Scholarship Council(CSC)Science Foundation Ireland(SFI)Chinese Academy of Sciences(CAS)(XDB16030700QYZDBSSW-JSC041)Science and Technology Commission of Shanghai Municipality(STCSM)(17XD1403900)
文摘Two-dimensional(2D) periodical Au and indium tin oxide(ITO) nanocomposite arrays have been fabricated based on a self-assembled nanosphere lithography technique. A button-shaped Au nanoparticle was formed on each hollow hemisphere-shaped ITO shell. Importantly, the underlying formation mechanism during the thermal treatment has been thoroughly explored by comparing structures resulting from different deposition conditions in detail. Compared to the Au nanoparticle arrays without ITO shells, the Au/ITO nanocomposite arrays showed a stronger localized surface plasmon resonance effect and higher absorption in the near-infrared(NIR) region, benefiting from the free-electron interaction enhancement between Au and ITO. The nonlinear optical properties were investigated using a modified femtosecond intensity-scan system, and the results demonstrated Au/ITO nanocomposite arrays with a remarkable two-photon absorption saturation effect for femtosecond pulses at 1030 nm. The versatile NIR optical responses indicate the great potential of the elaborately prepared 2D periodical Au/ITO nanocomposite arrays in many applications such as solar cells, photocatalysis,and novel nano optoelectronic devices.
文摘Currently,the fundamental judgment that China remains in an important period of strategic opportunities for its development has not changed,however new changes have taken place in the nature and the conditions of this period.On a higher starting point of development,China is faced with unprecedented opportunities for development as well as challenges unknown before.
基金the State Key Project of the National Social Science Foundation of China(No.19AZD003).
文摘This paper constructs a fixed effect model to study the impact of turnover of local government officials on local air quality,and the mechanism through which this effect takes place,using data from 282 prefecture-level cities in China from 2015 to 2019.This research shows that turnover of local government officials led to a decline in local air quality,mainly due to a“responsibility gap period.”It also found that the heterogeneity of officials and the difference in the implementation of political initiatives by cities affected the length of the“responsibility gap period”-the shorter it was,the lower the air pollution was during official turnover.Air pollution in China is still severe and the Chinese central government should therefore further reform the turnover system to improve local air quality during the turnover of key local officials by shortening the“responsibility gap period.”
